Combining Systems Thinking and Game Theory to Develop

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Combining Systems Thinking and Game Theory to Develop
Alternative Strategies for Assessing University Bursary Physical
Education in New Zealand Secondary Schools
Robert Y. Cavana
Senior Lecturer in Decision Sciences
Victoria Management School, Victoria University of Wellington,
PO Box 600, Wellington, New Zealand
Email: bob.cavana@vuw.ac.nz
Roger Moses
Principal, Wellington College,
PO Box 16-073, Wellington, New Zealand
Email: hmo@Wellington-College.school.nz
Abstract
This paper addresses the New Zealand Qualification Authority’s (NZQA) current
scaling practices for assessing University Bursary Physical Education (UBPE) in New
Zealand secondary schools. The scaling procedures being used are based on the raw
internally assessed marks provided by the secondary schools. Unfortunately, some
schools appear to be providing ‘inflated’ raw marks for UBPE, thus engaging in
‘game playing’. This has resulted in a great number of students and schools receiving
final marks for UBPE at much lower levels than they deserve. This paper analyses the
situation from Wellington College’s perspective and suggests that ‘systems thinking’
and ‘game theory’ could be employed in 2003 by secondary schools to combat the
ineffectiveness of NZQA in properly moderating UBPE assessments in the ‘game
playing’ schools. However, while ‘game theory’ may provide a rational solution to the
problem, it raises a number of ethical questions related to all stakeholders in the
system.
Keywords:
1.
NZQA, University Bursary Physical Education, Wellington College,
assessment strategies, systems thinking, game theory
Introduction
In the ‘University Entrance, Bursaries and Scholarships 2002 Candidate Information
Sheet’ supplied by the New Zealand Qualification Authority (NZQA), Forsyth (2003,
p2) states that:
The internally assessed marks submitted by schools may be scaled. This is to
ensure a fair and comparable standard between marks from different schools…
The scaling of internally assessed marks prevents candidates being advantaged or
disadvantaged by the particular school they attended.
…Hence standards in different subjects have to be comparable. This prevents
candidates being advantaged or disadvantaged by a particular choice of subjects.
Unfortunately, the students studying University Bursary Physical Education (UBPE)
at Wellington College (and similar schools) in 2002 were heavily ‘disadvantaged’,
due to the NZQA’s assessment procedures in this subject. This resulted in NZQA
scaling down Wellington College’s internally assessed raw marks for UBPE by an
average of 11.7% (or 5.9 marks) from a mean of 50.4 (C, a pass) to 44.5 (D, a fail)
out of 100. Also the students who received higher raw marks were scaled down more
both in absolute and in relative terms.
Figure 1
Comparison of Wellington College raw marks, NZQA adjusted WC marks &
NZQA final national distribution of marks for UBPE in 2002
(% distribution in each grade)
45%
Distribution in grade
40%
35%
30%
25%
WC raw marks
20%
NZQA adjusted WC marks
NZQA Final National Distribution
15%
10%
5%
0%
E (1-29%)
D (30-45%)
C (46-55%)
B (56-65%)
A (66-100%)
Grade (%graderange)
Source: Wellington College and NZQA (2003b)
Figure 1 shows that based on the professional judgement of Wellington College PE
teachers, 5 students (11%) should have received an A grade, and 8 students (17%)
should have received a B grade. However, NZQA severely scaled these results down
so that only 1 student (2%) at Wellington College received an A grade, and only a
further 3 students (6%) received a B grade.
Nevertheless, the NZQA (2003b) final national distribution demonstrates that on
average in a class of 47 students, 5 (or 11%) would receive an A grade and a further 7
(14%) would receive a B grade. In other words, 25% of the students in a typical
‘average’ New Zealand Physical Education class would receive an A or B grade. This
compares with 28% as assessed by Wellington College UBPE teachers for their 2002
bursary class, and 8% as finally scaled down by NZQA for this class.
The implication of the NZQA scaling was that Wellington College either provided
sub-standard education at bursary level Physical Education, or that the quality of
Wellington College UBPE students was well below the national average (or a
combination of both these). However, this is clearly not the case, since in recent years
an NZQA moderator had been to Wellington College and confirmed that the standards
were at the appropriate national level.
Although NZQA ranked Wellington College on the 25th percentile for UBPE in 2002
(222nd out of 295 schools (Colbert, 2003a)) the cohort of UBPE students at
Wellington College in 2002 was about the same academically as the average UBPE
class in New Zealand, hence the class should have been ranked on about the 50th
percentile (or about 147th out of 295 schools). This suggests that about 25% of the
secondary schools in New Zealand could have provided ‘inflated’ marks for UBPE in
2002 (we refer to this as ‘game playing’ in this paper).
There are a number of implications of the unfair scaling by NZQA of Wellington
College’s Physical Education bursary marks in 2002. These include:
•
•
•
•
Two students missed out on receiving a B bursary and one student an A
bursary as a result of this scaling, with 39% of the class receiving grades
below what they deserved based on the professional judgement of Wellington
College PE teachers.
Instead of 32% of the class receiving a failed grade (D or E) for the course,
NZQA scaling resulted in over half (51%) of the class failing UBPE.
The downgrading from a C average grade to a D (fail) average grade for the
UBPE class is also unfair to the PE teachers at Wellington College, as it
undeservedly reflects badly on them.
Students considering taking PE at Wellington College (and similar schools) in
2003 may have heard about the biased treatment by NZQA and may have been
discouraged from taking PE. This will also reflect badly for New Zealand
society, as the Government is currently trying to educate New Zealander’s to
lead healthier and better lives. This is in sharp contrast to the Hon Trevor
Mallard, Minister of Education’s comments in The Dominion Post (‘Let’s get
physical Mallard tells kids’, reported by Mulrooney, 2003):
“The objective for me is to get them off their backsides and into activities that
reduce the size of their backsides”
It was also particularly disturbing to see the trends in the difference between
Wellington College’s internally assessed UBPE mean mark and the lower final mean
mark provided by NZQA (see Figures 2 and 3). This has increased from about 0.5
marks in 2000 to nearly 6 marks lower in 2002. If this trend continues, the gap could
be even greater in 2003.
Figure 2
Wellington College UBPE Mean Marks:
2000 - 2002
Figure 3
Difference between WC raw and WC final NZQA
mean mark for UBPE: 2000-2002
54
50
National UBPE mean
mark
48
WC raw UBPE mean
mark
46
WC final UBPE
mean mark
44
2000
Marks
Marks
52
42
2000
2001
2001
0
-1
-2
-3
-4
-5
-6
-7
2002
Year
Source: Wellington College & NZQA (2003b).
2002
Difference
Year
This paper summarises a recent report prepared by Cavana and Moses (2003) that was
distributed by Wellington College to the Minister of Education, NZQA, and various
other educational bodies in New Zealand. The next section provides a brief rationale
for using systems thinking and game theory as analytical tools in this study. This will
be followed by a summary of the actual procedures currently being used by NZQA for
determining the final UBPE results. The next section briefly compares the
performance of the Wellington College UBPE results with other Wellington College
bursary results in 2002. Then the final marks for a selection of Auckland and
Wellington secondary schools taking UBPE in 2002 will be compared. This analysis
indicates that there appears to be some ‘game playing’ by some schools in New
Zealand (ie schools providing ‘inflated’ marks for their internal assessment of UBPE
above levels indicated by strictly adhering to NZQA guidelines). This leads us to the
use of system thinking and game theory as a means of developing and evaluating
alternative UBPE assessment strategies for Wellington College and similar schools.
Finally some concluding comments and recommendations are provided.
2.
Rationale for using Systems Thinking and Game Theory
From a systems thinking point of view, the trends outlined in Figures 2 and 3
represent a reference mode, which can be examined initially by developing causal
loop diagrams. These can be used to help diagnose the problem, and to identify
potential leverage points in the system for NZQA to intervene and correct the biases
that have emerged. If NZQA fails to take appropriate corrective action in 2003, we
suggest that Wellington College (and similar schools) then use game theory to help
develop alternative assessment strategies for UBPE to combat the distortions caused
by the ‘game playing’ secondary schools in New Zealand.
There do not appear to be many recent studies linking systems thinking / system
dynamics with game theory. Rabbino (1998) has discussed applying Brandenburger
and Nalebluff’s (1996) principles of Co-opetition (cooperation and competition using
game theory principles) with system dynamics tools; Kummerow & Quaddus (1998)
& Kummerow (1999) have analysed office market cycles and policies with a system
dynamics approach incorporating game theory; Gala et al. (1999) have undertaken a
system dynamics study of the Spanish telecommunications market using differential
game theory; and Warren (2002) has incorporated game theory into some of his
strategy dynamic models.
However, most of these studies incorporate game theory into a system dynamics
simulation model (eg see Forrester, 1961; Coyle, 1996; Sterman, 2000 or Maani &
Cavana, 2000 for further details about system dynamics). This study is different in
that it uses the problem structuring tools of system dynamics (ie causal loop diagrams)
to help explain the reasons for the historical behaviour patterns for the UBPE marks,
and then to show where the suitable intervention points are for NZQA to correct the
situation. Since we are just concerned with the situation in 2003 at this stage, we do
not develop a dynamic simulation model, but consider the choices for Wellington
College (and similar schools) using a static game theory framework.
3.
NZQA Scaling Procedures used by NZQA for PE Bursary Marks
The published information provided by NZQA does not fully explain how NZQA
arrives at the final UBPE marks for each candidate and for each school. NZQA
(2003a, p35) indicates that:
• “UB Physical Education is fully internally assessed…
• Marks for Physical Education for a particular school are moderated by the
final marks for the same group of candidates in all their other subjects. If the
mean of the marks submitted by the school for Physical Education differs by
more than 7 from the mean of the marks for the other subjects, the Physical
Education marks are adjusted for that school…”
Additional information was provided at a meeting at NZQA on 21 February 2003,
where the actual scaling process for UBPE was outlined more fully. This included the
following comments:
“The UBPE final mark given to each student is based on their percentile ranking from
the raw PE marks, applied to the list of ‘other’ UB subjects taken by the PE students.
For example, a PE student who ranked on the 50th percentile on the raw PE scores
will be assigned the mark on the 50th percentile of the other subjects taken by the PE
students.”
The underlying problem is that NZQA does not adjust the raw UBPE marks submitted
by each school to remove the inter-school biases (unless the mean of the raw marks
submitted by the school for PE differs by more than plus or minus 7 marks (ie a range
of 14 marks) from the mean of the marks for the other UB subjects taken by the PE
students in that class).
If a school follows closely the assessment guidelines provided by NZQA, then their
students will be ranked lower in the national averages for UBPE. Conversely, if a
school is an ‘easy’ or ‘generous’ marker, then their students will be ranked much
higher on the raw marks, and subsequently get higher final NZQA marks for UBPE
overall.
NZQA claims that equity in UBPE marking is assured by their system of moderation,
ie by going around the schools to ensure that UBPE teachers are marking at the
appropriate levels. The NZQA personnel admitted to us that generally UBPE teachers
around the country do NOT mark at the appropriate levels but mark higher. Hence it
would seem that their system of moderation is not working.
4.
Comparison with other Bursary Subjects at Wellington College
…Hence standards in different subjects have to be comparable. This prevents
candidates being advantaged or disadvantaged by a particular choice of subjects.
(Forsyth, 2003, p2)
It appears that Wellington College PE students have been seriously disadvantaged by
NZQA for choosing to study Physical Education at bursary level! Nearly every other
bursary subject at Wellington College in 2002 received a average pass grade of A, B
or C, compared with NZQA’s ‘failed’ average of D for Physical Education. Table 1
provides a comparison between the NZQA final scaled marks for PE and a range of
other Bursary subjects at Wellington College. There is some similarity in the cohort
of students studying PE and Geography, hence one would have expected that the
mean mark for UBPE would have been about 50% or similar to the internally assessed
mark, rather than the final NZQA mean mark of 44.5%.
Table 1
Comparison of NZQA Final Adjusted Bursary Marks at Wellington College in 2002
Bursary Subject
Physical Education
Geography
English
Maths with Statistics
History
Biology
Mean of NZQA final
adjusted marks
(%)
44.5
55.5
62.4
54.1
57.3
61.3
Ave Grade
D
C
B
C
B
B
Number of WC
students
(No.)
47
53
123
136
48
46
Source: NZQA (2003b)
5.
Comparison of Selected Auckland and Wellington Secondary School’s PE
Bursary Marks
The scaling of internally assessed marks prevents candidates being advantaged or
disadvantaged by the particular school they attended.
(Forsyth, 2003, p2)
Although we are not suggesting which are the ‘easy’ marking schools, it is interesting
to compare the final performance in UBPE in 2002 of a range of Auckland schools
compared with a range of Wellington schools. Table 2 indicates that on average 10%
of the students taking PE at the selected Auckland schools were awarded a scholarship
compared with none at the Wellington schools. Overall nearly 42% of the students at
these Auckland schools were awarded a scholarship, A or B grade in UBPE,
compared with just 15% at the Wellington schools. Also the NZQA web site data
indicates that the average final mark for UBPE in the Auckland schools was 56%
compared with just 45.3% in the Wellington schools.
Table 2
University Entrance, Bursaries and Scholarships 2002 Physical Education Grade
Distributions for Selected Auckland and Wellington Secondary Schools
(Percentage grade distribution)
Auckland Grammar
School
King's College
Rangitoto College
Takapuna Grammar
School
Westlake Boys' High
School
Ave Selected Auckland
Schools
Hutt Valley High School
Rongotai College
St Patrick's College
(Silverstream)
St Patrick's College
(Wellington)
Wellington College
Ave Selected
Wellington Schools
All New Zealand Schools
Total
Schol.
A
B
C
D
E
72
29
56
11.1
0
8.9
16.7
34.5
12.5
22.2
10.3
7.1
30.6
34.5
50
18.1
13.8
19.6
1.4
6.9
1.8
36
16.7
13.9
16.7
22.2
19.4
11.1
37
13.5
13.5
10.8
32.4
21.6
8.1
46
10.0
18.2
13.4
33.9
18.5
5.9
25
12
0
0
0
0
4
0
56
66.7
32
33.3
8
0
35
0
5.7
20
34.3
25.7
14.3
17
47
0
0
5.9
2.1
29.4
6.4
17.6
40.4
29.4
44.7
17.6
6.4
27
0.0
2.7
12.0
43.0
33.0
9.3
3,962
2.5
8.5
14.2
39.3
28.5
6.9
Source:New Zealand Qualifications Authority, web site:
http://www.nzqa.govt.nz/qualifications/ssq/statistics/school/, accessed 7 August 2003
The differences are further highlighted when a comparison of the percentile scores is
done. For example the mark for the 75th percentile for the Auckland schools was
68%, which is higher than the mark for the 95th percentile for the Wellington schools!
What this implies is that the top 25% of UBPE candidates in the Auckland schools
have performed better than 95% of UBPE candidates from the Wellington schools.
Although some difference does exist between the overall academic standards at the
Auckland schools compared with the Wellington schools, this is most unlikely and
suggests an element of ‘game playing’ by some Auckland schools, providing inflated
raw marks for UBPE.
6.
Systems Thinking Analysis of the PE Bursary Marks
The situation outlined in the previous sections indicates that some schools appear to
be engaging in ‘game playing’ to inflate their internally assessed UBPE marks to
higher levels than the levels indicated by the NZQA guidelines. Also many schools
are still strictly adhering to the NZQA guidelines and are performing relatively worse
in terms of their final NZQA marks for UBPE. As a consequence, the morale of the
staff and students from these ‘non-game playing’ schools is also suffering and
declining. This situation is reflected in Figure 4. Line (1) indicates the increasing
UBPE marks and morale at the ‘game playing’ schools, whereas line (2) indicates the
decreasing UBPE marks and morale at the ‘non-game playing’ schools. The
unbroken lines represent the historical behaviour, whereas the small dotted lines
represent the expected trend during 2003 if nothing different is done by NZQA (or the
secondary schools collectively) to change this trend. The dashed lines (3) indicate a
scenario whereby NZQA actively intervenes to moderate the school’s internal
assessments for UBPE much more carefully and consistently, or takes more
appropriate corrective action to adjust inflated raw UBPE marks submitted by ‘game
playing’ schools.
Figure 4
Behaviour over time chart comparing morale and UBPE marks
for ‘game playing’ and ‘non-game playing’ schools
(1) Marks/morale at ‘game playing’ schools
(3) Marks/morale at schools with
appropriate NZQA interventions
(2) Marks/morale at ‘non-game playing’ schools
2002
2003
We can now analyse the behaviour over time chart in Figure 4 above by utilising
some of the systems thinking tools outlined in Maani and Cavana (2000). In
particular, we will show how the causal loop diagrams in Figures 5 & 6 can help us
analyse the situation.
Figure 5: Initial Reinforcing Feedback Loop (R1) for ‘Game Playing’ Schools
s
Proportion of PE schools
‘game playing’
s
Raw UBPE marks from
‘game playing’ schools
R1
s
Ranking of UBPE
students from ‘game
playing’ schools
Morale of UBPE
staff/students from ‘game
playing’ schools
s
s
Final NZQA UBPE
marks for ‘game playing’
schools
Key to Figs 5 & 6:
R1
B1
o
s
Reinforcing loop – are positive feedback systems. They can represent growing or declining
actions.
Balancing loop – seeks stability or return to control, or aims for a specified target
Variable at the head of an arrow changes in the opposite direction to the variable at the tail.
Variable at the head of an arrow changes in the same direction as the variable at the tail.
We can analyse the variables and their relationships around the reinforcing feedback
loop R1. We can start by observing that there appears to have been an increase in the
number and proportion of secondary schools that have been involved in ‘game
playing’ and submitting higher UBPE raw marks to NZQA. These higher raw marks
result in higher rankings for the students of these ‘game playing’ schools and in
higher final UPBE marks for these students, since the final NZQA rankings are based
on the initial raw marks. This leads to an increase in the morale of teachers and
students from these schools, which has a further reinforcing (increasing) effect on the
proportion of schools involved in game playing, thus starting the cycle off again. We
can now add the effects on the ‘non-game playing’ schools onto this diagram. This is
shown in Figure 6 below.
We have now added the extra variables and links that make up the second reinforcing
feedback loop (R2) in this diagram. If we start our analysis again by considering that
a higher proportion of ‘game playing’ schools will lead to higher raw UBPE marks
submitted by these schools. However, because of the way NZQA ranks UBPE
students on the basis on unadjusted raw UBPE marks, this will now result in lower
rankings for UBPE students from ‘non-game playing’ schools, and hence lower final
NZQA marks for these UBPE students and subsequently the morale of both the UBPE
staff and students from these schools will suffer and decline. This will result in some
schools changing their UBPE assessment strategies, and marking more generously the
following year (eg in 2003), causing the first reinforcing loop (R1) to grow much
more quickly. Hence this behaviour, based on the discussion of the reinforcing
feedback loops, is illustrated in Figure 4 above. This is a good example of Peter
Senge’s ‘Success to the Successful’ systems archetype (Senge, 1990, pp385-386),
whereby the ‘game playing’ schools are rewarded with higher final UBPE marks.
This behaviour, illustrated by lines (1) and (2) in Figure 4, can be averted by NZQA
intervening at two leverage points in the system. The first point is indicated by point
(A) in Figure 6, whereby NZQA can moderate more effectively the internal
assessment of UBPE at all schools in New Zealand. The second leverage point is
indicated by point (B). This indicates that if NZQA can not moderate the schools’
internal assessment procedures appropriately, then it could intervene when it receives
all the internally assessed raw UBPE marks by the schools, and make the appropriate
corrections for bias then.
However, in recent years NZQA has consistently not intervened appropriately at the
two leverage points identified in Figure 6. Hence we would recommend that ‘nongame playing’ schools might consider the implications of game theory discussed in
the next section, and perhaps adjust their UBPE assessment strategies to overcome the
bias caused by NZQA’s failure to address the ‘game playing’ schools fairly.
Figure 6: Causal Loop Diagram for UBPE Assessments System
Morale of UBPE
staff/students from ‘nongame playing’ schools
Final NZQA UBPE
marks for ‘non-game
playing’ schools
s
s
(A)
Ranking of UBPE
students from ‘non-game
playing’ schools
R2
NZQA moderation
of schools PE
assessment
o
o
s
Proportion of PE schools
‘game playing’
s
Raw UBPE marks from
‘game playing’ schools
R1
s
Ranking of UBPE
students from ‘game
playing’ schools
Morale of UBPE
staff/students from ‘game
playing’ schools
s
s
Final NZQA UBPE
marks for ‘game playing’
schools
(B)
NZQA corrective
actions on ‘inflated’
raw marks
7.
Assessing UBPE Performance using Game Theory
Unfortunately, with NZQA failing to adequately correct biases in the raw marks
submitted by ‘game playing’ schools for UBPE, this now leaves ‘non-game playing’
schools in a position of having to ‘guess’ what the assessment strategies might be by
the other schools. Fortunately a well developed body of literature called ‘game
theory’ has been developed to help schools out in this situation.
The classic source for game theory is John von Neumann and Oskar Morgenstern’s
(1947) book, ‘Theory of Games and Economic Behaviour’. Considerable literature is
now available on this subject, including, for example Binmore (1990), Brandenburger
and Nalebuff (1996), Romp (1997), Fisher & Waschnik (2002) and Watson (2002).
However, we will use some of the ideas presented by Baumol (1965) here. For
example, Baumol (p530) suggests that with game theory:
“It is possible to approach the analysis of competitive behaviour by a more
deductive route. Instead of asking, inductively, what we can infer from the
competitor’s past behaviour, one seeks to determine a rival’s most profitable
counterstrategy to one’s own “best” moves and to formulate the appropriate
defensive measures.”
By competitor, we are now referring to the ‘game playing’ schools that offer UBPE,
since it is by their ‘assessment strategies’ that Wellington College’s relative ranking
in UBPE has declined. This is evident from Figures 2 & 3, which show that the gap
between Wellington College’s internally assessed UBPE mean mark and the final
mean mark provided by NZQA has increased significantly over the last few years. If
this trend continues, the gap could be even greater in 2003, as more New Zealand
schools adopt a more ‘generous/inflated’ marking strategy for UBPE.
The situation that Wellington College (and similar schools) face can be analysed as a
‘two person, constant-sum’ game (Baumol, 1965, p530). The final marks and
percentile distribution for UBPE are based on the UBPE candidates performances in
their ‘other bursary’ subjects, but the actual percentile for each UBPE candidate (and
mean for the school) depends on their ranking based on the raw UBPE marks
submitted by each school. Hence each school can vary their strategy on how they
mark. We will define three illustrative strategies how each school might internally
assess their UBPE marks:
Strategy 1
Strategy 2
Strategy 3
Assess strictly according to NZQA guidelines
Assess ‘more generously’ than NZQA guidelines (ie provide an
average of about 5 more marks for the UBPE class than Strategy 1)
Assess ‘very liberally’ compared to NZQA guidelines (ie provide an
average of about 10 more marks for the UBPE class than Strategy 1)
Now to help us with this analysis, we can regard the ‘game’ as being played by two
players: Wellington College and all the other ‘game playing’ schools combined taking
UBPE in 2003 (called ‘Other Schools’ here). For each strategy taken by Wellington
College, a ‘payoff’ can be calculated depending on the strategy selected by the Other
Schools. The payoff is measured by an indicative mean final mark for UBPE for
Wellington College. The strategies and payoffs are summarised in the Payoff Matrix
in Table 3 below. About 25% of secondary schools in New Zealand offering UBPE
are estimated to be engaged in ‘game playing’ behaviour.
Table 3
Payoff Matrix for Evaluating Wellington College’s UBPE Assessment Strategies
(mean percentage mark for WC UBPE)
Other Schools’ Strategy
Wellington
College
Strategy
1
2
3
1
48%
44%
41%*
2
52%
48%
44%*
3
55%_
52%_
48%*_
In practice any number of strategies are possible, but we have simplified them to 3
strategies each in Table 3 to illustrate the analysis. For example in the year 2000,
Wellington College employed strategy 1 in strictly assessing UBPE according to
NZQA guidelines. By and large most of the Other Schools also appeared to be
following Strategy 1 and Wellington College ended up with a final mean UBPE mark
of nearly 48%, similar to its internally assessed raw mean mark (see Figure 2).
However, by 2002 Wellington College was still assessing strictly to NZQA guidelines
(ie strategy 1) but meanwhile the Other Schools appeared to be on average marking
‘more generously’ (ie strategy 2) and Wellington College received a final mean UBPE
mark of about 44%.
As can be seen in Table 3, if both Wellington College and the Other Schools adopt the
same strategies, then their payoffs will be the same, ie the average mean UBPE final
mark for Wellington College will be 48%. For example, if both Wellington College
and the Other Schools adopt ‘very liberal’ assessment strategies (strategy 3), then
their students’ relative rankings on their raw UBPE marks will be the same as if they
both adopted very strict (strategy 1) or ‘more generous’ assessment strategies
(strategy 2). In some respect this would be the ‘fairest’ outcome if NZQA does not
take corrective action for ‘game playing’ schools in 2003. That is, if all NZ secondary
schools offering UBPE in 2003 agree to follow one of the strategies outlined here!
The other payoff values shown in Table 3 have been estimated based on the strategies
employed by each ‘player’. These should be regarded as only indicative mean final
UBPE marks for Wellington College.
The lowest payoff is estimated to be 41%, 7 marks below the 48% (the average of the
‘other bursary’ subjects taken by Wellington College PE students in 2002 who took 3
or more bursary subjects), and the highest payoff is given by a mean UBPE final mark
of 55%, or 7 marks above the average mark for the ‘other UB subjects’. In other
words, there is a range of 14 marks that Wellington College could receive final UBPE
mean marks from NZQA, depending on which strategies Wellington College and the
Other Schools take! This is an immense variation currently outside the ‘control’ of
NZQA.
7.1
Maximin and Minimax Strategies
Following Baumol (1965, pp530-534), we can now evaluate this payoff matrix to
determine if there are optimal strategies, which both Wellington College and the
Other Schools can take. We will also make the assumption that both players have full
information about each other’s strategies and can play any of the strategies in total.
We will now assess the maximin and minimax strategies, since “the cautious approach
to this problem is to assume the worst and act accordingly” (Baumol, 1965, p531).
Firstly, we will examine Wellington College’s maximin strategy. For each strategy
taken by Wellington College we will assume that the Other Schools adopt the strategy
that will maximise their mean final UBPE mark. For example, if Wellington College
adopts strategy 1, then we assume that the Other Schools will adopt strategy 3, since
Wellington College will end up with a mean PE mark (41%) below the average and
the Other Schools will end up with a mean UBPE mark above the average of 48% (the
actual mark does not matter here and it will depend on the number of UBPE
candidates in the Other Schools relative to the number of candidates in Wellington
College.). We note this mark with an asterisk (*) to indicate the optimal strategy for
the Other Schools. Similarly when Wellington College employs strategy 2, the Other
Schools will also select their strategy 3, since it will minimise Wellington College’s
mean PE mark, and thereby maximise their own students’ marks. This value (44%) is
noted with an asterisk. So is the value of 48% when Wellington College selects
strategy 3, the Other Schools will select their strategy 3 also. Now the optimal
maximin strategy for Wellington College is to select the strategy that will maximise its
average UBPE mark, ie “choose that one among its strategies for which the starred
figure is highest…the maximum among these minimal payoffs” (Baumol, 1965,
p532). That will occur when Wellington College employs strategy 3, ending up with
a mean final UBPE average mark of about 48%. This is called their maximin strategy
(ie the strategy that maximises the minimum payoffs for each of Wellington College’s
strategies).
The Other Schools can employ a similar approach (evaluating their minimax strategy).
The worst for them is when Wellington College receives a high mean mark for UBPE,
since that means they will receive a relatively lower mark. Now if the Other Schools
adopt strategy 1, then the worst ‘payoff’ to them is if Wellington College adopts
strategy 3 and receives a mean mark of 55%. This figure is marked with a prime.
Similarly if the Other Schools play strategies 2 and 3 then the worst payoffs in each
column (or highest mean marks for Wellington College) are marked with a prime
also. The best of these pessimistic payoffs for the Other Schools is the lowest of these
average Wellington College mean UBPE marks, which is 48%. Hence the best choice
for the Other Schools is strategy 3, which is called their minimax strategy (ie the
strategy that minimises the maximum payoffs for Wellington College under each of
the Other Schools strategies).
Now we can compare the maximin strategy for Wellington College, with the minimax
strategy for the Other Schools to see if a ‘saddle point’ or ‘equilibrium point’ exists.
In this case Wellington College’s average mean UBPE mark of 48% from its maximin
strategy 3 is exactly the same as the mean mark that the Other Schools expect
Wellington College to receive when the Other Schools employ strategy 3 (ie the
starred mark in row 3 coincides with the primed mark in column 3). Hence an
equilibrium point does exist, and both Wellington College and the Other Schools
would be best off employing strategy 3 (ie a ‘very liberal’ assessment of UBPE raw
marks compared with NZQA guidelines).
7.2
Decision Making Under Uncertainty
“Decision making under uncertainty requires that the decision maker use his
judgement and experience about future events” (Bierman et al. 1969, p9). We can
now extend the analysis described above to incorporate some of the ideas from
decision theory ( eg see Baumol, 1965; and Bierman et al. 1969). In this situation the
strategies employed by the Other Schools are considered ‘states of nature’ or
‘environmental states’ outside of the influence of Wellington College, and also
independent of the actions of Wellington College. In some respects this is more
realistic than the game considered above whereby Wellington College employs its
minimax strategy 3, and the Other Schools respond by selecting their maximin strategy
3, thereby reaching an equilibrium point. In this analysis we assume that the Other
Schools will employ their strategies irrespective of the strategies that Wellington
College employs. However, we can attach probabilities to the likelihood of the Other
Schools employing a specific strategy. In this case we assume that there is only a 5%
chance that the Other Schools will return to strategy 1 (strictly following NZQA
guidelines); an 80% chance that they will follow strategy 2 (more generous
assessments) and a 15% chance that they will follow strategy 3 (very liberal
assessment procedures). Sensitivity analysis can be undertaken to vary these
probabilities.
This additional information is incorporated into the extended payoff matrix in Table 4.
The expected value (or weighted average) for each of Wellington College’s strategies
can be calculated as follows:
Expected value of WC strategy 1 = 0.05 * 48% + 0.80 * 44% + 0.15 * 41%
= 43.8%
Similarly, the expected values for Wellington College’s strategy 2 and 3 are 47.6%
and 51.6% respectively. Now Wellington College can select the strategy that
provides the highest expected mean mark for UBPE. This occurs for strategy 3.
Hence using this ‘expected value’ decision criterion, Wellington College would be
encouraged to employ ‘very liberal’ assessment procedures compared to NZQA
guidelines (ie strategy 3). This analysis supports the decision reached above under the
analysis of maximin and minimax strategies.
Table 4
Payoff Matrix for Evaluating Wellington College’s UBPE Assessment Strategies
under Uncertainty
(mean percentage mark for WC UBPE)
Other Schools’ Strategy
(environmental states)
Wellington
College
Strategy
Probability
Expected WC
mean UBPE
mark
1
2
3
1
48%
44%
41%
43.8%
2
52%
48%
44%
47.6%
3
55%
52%
48%
51.6%*
0.05
0.80
0.15
However, while this ‘rational analysis’ indicates that Wellington College should
pursue its interests by following strategy 3, this raises some very important ethical
issues:
(1) Should schools be involved in ‘game playing’ to ensure that their students and
staff get fair assessments under the present NZQA UBPE assessment
procedures?
(2) Is this ‘game playing’ ethical?
(3) What happens to the students that fail Bursary or get lower marks than they
deserve in UBPE, because NZQA has failed to moderate the schools internal
assessment properly, or has failed to take the appropriate corrective action
when they have learned that some schools are not following NZQA guidelines
as strictly as they should?
(4) Is NZQA’s current behaviour ethical?
(5) What about the short and long term effects on the disadvantaged students?
(6) What happens to the schools that don’t understand a ‘game’ is being played
with the internal assessment of UBPE by an increasing number of schools?
Will they be increasingly more disadvantaged in the 2003 UBPE final
assessments by NZQA?
8.
Conclusions & Recommendations
University Bursary Physical Education at secondary schools in New Zealand is a
demanding and challenging subject, which requires a high level of physical and
intellectual skills and ability to be able to perform well in it. It is also regarded as a
significant university subject, with Physical Education graduates from New Zealand
universities performing many valuable roles in the wider New Zealand society and in
the international community.
There appears to be no reasonable justification for NZQA’s excessive scaling down of
Wellington College’s University Bursary Physical Education marks in 2002, from an
average of 50.4 (C ) to a ‘failed’ average of 44.5 (D). A case was made to NZQA
(Cavana, 2003a; Moses, 2003a, b & c) and the Minister of Education (Cavana, 2003a,
b & c) to have these marks scaled back up to the average of the marks submitted by
Wellington College’s Physical Education teachers, which were at similar levels to the
final NZQA national distribution of bursary marks. However, this case was rejected
by NZQA (Colbert, 2003a & b) and by Hon Trevor Mallard (2003a & b), the Minister
of Education.
This paper has further investigated the situation and has applied systems thinking and
game theory to demonstrate how Wellington College (or similar schools) can employ
different assessment strategies to counterbalance NZQA’s failure to correct for the
higher marks generated by the ‘game playing’ schools in New Zealand. Nevertheless,
while Wellington College and similar schools can also adopt ‘game playing’ to
improve their marks and morale in UBPE in 2003, this raises a number of ethical
issues related to all stakeholders in the system (ie the schools, UBPE candidates and
staff, and NZQA).
Based on this analysis, we recommend that NZQA review their 2003 procedures for
moderating the internal school assessment of UBPE and the ranking of unadjusted
raw UBPE marks as the basis for the assessment of the final UBPE marks. However,
if NZQA will not take the appropriate corrective action in 2003 against the ‘game
playing’ schools, then the fairest outcome would occur if all schools that offer UBPE
in New Zealand in 2003 adopt the same assessment strategy (ie assess UBPE
compared with NZQA guidelines either ‘strictly’; ‘more generously’; or ‘very
liberally’). This will ensure that the outcomes in 2003 for UBPE for students and
staff are ‘relatively fair’ and the distortions and biases from ‘game playing’ schools
will be removed as much as possible.
The Minister of Education has advised us that: “From 2004 the University Bursaries
award will be replaced with NCEA. Under this award all school assessment decisions
will stand, avoiding the need for any statistical moderation” (Mallard, 2003b, p2).
However, this would appear to actually increase the value of this research, because
from 2004 onwards there will be a larger internally assessed component in all final
year subjects at secondary schools in New Zealand.
Finally we would like to suggest that this paper contributes to the systems thinking
literature, by demonstrating how systems thinking and causal loop diagrams can be
used in conjunction with game theory to resolve important issues of concern to
managers and other stakeholders in situations involving risk and uncertainty.
Acknowledgements
We would like to acknowledge the assistance of all the people who have helped in the
preparation of this paper. In particular we would like to thank Messrs Robert
Anderson, Chris Pollock, Chris Wells and Mrs Heather Oldershaw at Wellington
College; Professors Cedric Hall and John Prebble at Victoria University of
Wellington; various staff members at the New Zealand Qualifications Authority for
all their assistance; and the anonymous ANZSYS referees for their comments.
However, the opinions and interpretations in this paper remain the authors’ own.
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